Immune thrombocytopenia (ITP) is an immune-mediated hematologic disorder, characterized by isolated thrombocytopenia (peripheral blood platelet count less than 100 × 109/L) (1), without a clinically apparent cause. Among involved mechanisms, the presence of platelet-directed antibodies and decreased bone marrow production are considered the driver events of ITP pathogenesis. ITP cases have been described following several viral infections, including cytomegalovirus (CMV), hepatitis B/C viruses (HBV/HCV), varicella zoster virus (VZV), human immunodeficiency virus (HIV), and most recently, following COVID-19. Furthermore, rare cases of ITP were observed after measles-mumps-rubella (MMR) and varicella vaccines, but the real incidence of secondary ITP after other types of vaccines is almost unclear.
We here present the case of a 31-year-old female developing, after 3 weeks from SARS-CoV2 vaccination, a severe ITP refractory to corticosteroids and IVIGs, treated with thrombopoietin (TPO) mimetic.
Case Report
A 31-year-old healthy woman with no prior drug use, received the COVID-19 vaccine through his work as pharmacist employee. After 3 weeks, post-vaccination, she presented to the emergency room due to the occurrence of widespread petechiae and gum bleeding. She did not report recent respiratory and gastrointestinal symptoms or a history of infections. She had not personal history of bleeding or autoimmune disease, while she reported that her father had chronic myelogenous leukemia and vitiligo. Vital signs were normal, no hepatic or splenic enlargement was observed, no focal neurological deficits were noted. Laboratory tests revealed normal white-cell count (WBC = 6.240/µl), hemoglobin (12 g/dl), and severe thrombocytopenia with a platelet count of 1000/ul. Morphologic analysis of peripheral blood smear confirmed thrombocytopenia, without clumping.
Her PCR assay was negative for SARS-CoV-2. One month prior to receiving the vaccine, the patient was evaluated for a routine laboratory screening for her job, and complete blood count reported normal platelet count of 200.000/uL.
At the emergency department, the following labs were normal or negative: creatine, electrolytes, bilirubin, LDH, haptoglobin, prothrombin time, partial thromboplastin time, fibrinogen, aspartate aminotransferase and alanine aminotransferase and total protein. In addition, she was negative for Hepatitis B, Hepatitis C antibody, HIV and Epstein–Barr Virus serology.
Bone marrow biopsy demonstrated absence of immature cells, normocellular trilineal hematopoiesis with strong increase of megakaryocytes. Flow cytometry was normal. A computerized tomography (CT) total body scan did not show organs hemorrhagies or lymphoadenomegalies. Autoimmunity tests performed on day 2 for anti-nuclear antibody (ANA), anti-extractable nuclear antigen (ENA), antineutrophil cytoplasmic antibody (ANCA), rheumatoid factor (RF), anti-dsDNA, anti-smooth muscle antibody (ASMA), anti-Platelet (ab-PLT), anti-Thyroglobulin (anti-Tg) and anti-Thyro peroxidase (anti-TPO) were normal.
On the basis of clinical presentation, a platelet count < 100.000/uL, and the exclusion of other causes of thrombocytopenia, a diagnosis of ITP was made (1).
At this point, the patient was admitted to our Hematology department and a therapy with platelet transfusion, high dose corticosteroids (methylprednisolone 1 mg/kg/day) and intravenous immunoglobulin at 1 g/kg for 2 days, was started (Fig. 1).
On day four, petechiae and oral bleeding decreased, and the platelet count was 57.000/uL. However, after 11 days from start of therapy, epistaxis episode occurred, hemogram showed very low platelet count with PLT 9.000/ul, and the patient was started again on platelet transfusion (Fig. 1).
At that time, in consideration of refractory ITP to standard therapy with corticosteroids or immunoglobulins, eltrombopag (50 mg) treatment was started. On day 18, the patient's platelet count normalized to 150.000 /uL, with disappearance of any bleeding symptoms and she was admitted to clinical-laboratoristic follow-up (Fig. 1).